I've heard people discuss the 'unreliable narrator' for years, but I never really understood the joy or appreciation of this narrative mode - until I read Rebecca Stead's Liar and Spy. (Which fabulously just won the Guardian children's fiction prize.)
Maybe it's because Georges is really hiding from circumstances he can't handle, maybe it's because of how he's being treated at school, but you sympathize with him. And, if you reach the end of the book not knowing his status, it's not THAT big of a surprise. Not like the other liar in the book. In fact, when you get to the end you realize that Georges has really been the spy all along.
There are many other books where the unreliable narrator is a less sympathetic character, usually for good reason. One such book would be Justine Larbalestier's brilliant Liar. Hmm...I'm beginning to see a title trend.
The narrator, Micah, is a compulsive liar, who initially, mischeviously, fools her whole school into believing she is a boy. The lies get progressively darker from there.
There are many out there to try - here are some notable options:
I know, it's more than 5. I lied.
More Unreliable Narrators on Library Thing